The present invention relates to an image display apparatus, and more particularly to a projection display apparatus technology.
The ability of a projection display apparatus to take input images and display them enlarged on a screen has led to the extensive use for presentations. In a presentation a commentary accompanies the images projected onto the screen. Generally, multiple pages of presentation images are used. While each page of presentation images is different, usually a number of the images are interrelated, so it is necessary to cut back and forth between related presentation pages. Therefore, users want to be able to simultaneously display at least some of multiple pages of interrelated presentation images.
Also, during question and answer sessions or when a short time is needed before a new set of images can be displayed, companies like to display corporate logos, products and other such images (which will also be referred to as specific images) instead of presentation images. In the prior art, specific images were supplied to the projection display apparatus via an image source apparatus such as a computer, video player, TV receiver or the like. Thus, the problem has been that the specific image data has had to be stored beforehand in the image source apparatus connected to the projection display apparatus.
When no images are being input to the projection display apparatus the screen remains blank. In such situations, in the prior art the projection display apparatus displays a one-color screen image called a blank image. In this situation too, users have expressed a desire to display specific images. However, this has not been possible because normal images are not being input from the image source apparatus. This problem is not limited to the projection display apparatus, but is also shared by image display apparatus that display images supplied externally.
This invention was accomplished to overcome the foregoing problems of the prior art. A first object of the invention is to provide a technology that enables related portions of multiple pages of images to be displayed simultaneously. A second object is to provide a technology that enables specific images to be displayed even when the specific images are not supplied externally.
In accordance with a first aspect of this invention, the above object is attained by a projection display apparatus that comprises: an image extraction section that extracts at least a portion of given first image data as an extraction image; an extraction image memory for storing extraction image data representing the extraction image; an image overlay section that generates overlaid image data by superimposing the extraction image on original image represented by given second image data; a light modulation unit that is driven responsive to the overlaid image data pixel by pixel; and an optical system for projecting onto the screen the overlaid image obtained by the light modulation unit.
Since this projection display apparatus contains a section for extracting at least a portion of a given image, and an image overlay section for superimposing the extracted image on the original image, it is possible to simultaneously display multiple pages of interrelated image portions.
It is preferable that the image extraction section can arbitrarily set the portion to be extracted from the first image data, since this makes it easier to produce extraction image data for a particular purpose.
It should also be possible for the image overlay section to superimpose the extraction image at a desired position on the original image, since that provides more freedom with respect to overlaying extraction images.
It is also preferable that the extraction image memory stores a plurality of extraction image data representing a plurality of extraction images, and the image overlay section superimposes at least one selected extraction image at each specified position on the original image.
Doing this makes it possible to select an arbitrary extraction image from among a plurality of extraction images, enabling a desired extraction image to be overlaid on an original image.
It is preferable for the image overlay section used in the projection display apparatus to be equipped with a synthesizer section that generates the overlaid image data by synthesizing the given second image data and the extraction image data read out from the extraction image memory; and a frame memory for storing the overlaid image data, the frame memory having at least a memory area corresponding to all the pixels of the light modulation unit. In this case, the overlaid image data read out of the frame memory is supplied to the light modulation unit.
With this configuration, since image data consisting of the extraction images superimposed on the original image is written to a frame memory, the overlaid image can be obtained by reading the overlaid image data from the frame memory.
Alternatively, It is preferable for the image overlay section used in the projection display apparatus to be equipped with a frame memory for storing the given second image data, the frame memory having at least a memory area corresponding to all the pixels of the light modulation unit; and a synthesizer section that generates the overlaid image data by synthesizing the second image data read out from the frame memory and the extraction image data read out from the extraction image memory, with the overlaid image data synthesized by the synthesizer section being supplied to the light modulation unit.
This configuration allows the overlaid image data to be obtained in the projection display apparatus. Thus, this projection display apparatus has the same function and advantage as the preceding apparatus. Compared to the preceding configuration in which the overlaid image data is read out of the frame memory and displayed, in this configuration the extraction image is superimposed as the image data is being read out of the frame memory. Therefore, the time taken from the initial overlay command to the display of the overlaid image is shorter.
In another preferred arrangement, the synthesizer section comprises a data selector that selects either one of the second image data and the extraction image data, pixel by pixel, to produce the overlaid image data.
With this configuration, since the data selector selects either one of the second image data and the extraction image data, an extraction image can be superimposed on the original image by substituting extraction image data for part of the original image data.
It is preferable for the synthesizer section to be equipped with a multiplier section that multiplies the second image data and the extraction image data by respective coefficients on a pixel by pixel basis; and an adder section that adds the multiplied second image data and the extraction image data on a pixel by pixel basis.
With this configuration, the coefficients can be used to adjust the density ratio between the embellishment image and the original image.
In another preferred configuration, the synthesizer section comprises a coefficient setting section that controls the coefficients in the multiplier section to change a synthesis ratio between the second image data and the extraction image data, thereby adjusting a degree of transparency of the extraction image superimposed on the original image.
Doing this enables the synthesis ratio between the image data and the extraction image data to be altered by controlling the coefficients of the multiplier section, making it possible an overlay image in which the portion overlaid by an extraction image is transmitted.
In the above projection display apparatus, also, it is preferable that the coefficient setting section changes the coefficients in the multiplier section with time to change the synthesis ratio between the second image data and the extraction image data, thereby changing the degree of transparency of the extraction image superimposed on the original image with time.
Doing this makes it possible to change with time the degree of transparency of the portion on which an extraction image is overlaid by changing the coefficients of the multiplier section with time.
A projection display apparatus according to a second aspect of the invention comprises: a frame memory for storing image data representing an image to be displayed; a image display signal generator for generating image display signals based on the image data stored in the frame memory; a electro-optical device for emitting light to form images responsive to the image display signals; a projection optical system for projecting light emitted by the electro-optical device; an image extraction section that extracts at least a portion of an extraction target image selected arbitrarily from among images given externally as an extraction image; an ex traction image memory for storing extraction image data representing the extraction image; and a specific image display control section that in a specific display condition displays a specific image represented by specific image data including the extraction image data stored in the extraction image memory.
With this configuration, at least a part of a selected target image can be acquired as the extraction image. In a specific display condition, this makes it possible to display specific image that include arbitrarily extracted image, in place of image given to the projection display apparatus. Thus, desired specific image can be displayed even when specific images are not being supplied from an external source.
In another preferred configuration, the image extraction section implements the steps of: displaying an extraction image setting screen for setting image extraction conditions comprising at least an extraction area and an extraction magnification factor; displaying an extraction area specifying image used in setting the extraction area on the extraction target image; when the extraction area is set with the extraction area specifying image, writing into the frame memory selected extraction image data representing a selected extraction image corresponding to the set extraction area; when a display magnification factor is set, enlarging or reducing the selected extraction image data based on the magnification factor and writing the enlarged or reduced selected extraction image data into the frame memory; and when a desired display magnification factor is determined, storing the selected extraction image data enlarged or reduced based on the desired display magnification factor in the extraction image memory.
The extraction image setting screen makes it easier to set the target extraction image area. Also, before a magnification factor is determined, it can be checked by displaying the selected extraction image corresponding to the set extraction area at the selected magnification factor concerned.
In another preferred arrangement, the image extraction section displays a predetermined extraction frame as the extraction area specifying image, the predetermined extraction frame having a first black outline, a second black outline inside the first black outline and a white area between the first and second black outlines.
This facilitates setting the extraction area by making it easy to distinguish the extraction area on the extraction target image. Whatever the color of the extraction target image is, black outlines or white image frame can be displayed clearly.
In another preferred arrangement, the extraction image memory stores a plurality of extraction image data representing a plurality of extraction images; and the specific image display control section displays a specific image that include at least one extraction image selected from among the plurality of extraction images in the specific display condition.
A specific image display control section can be used that selects at least two of the extraction images from among the plurality of extraction images and displays the selected images in order.
The ability to choose from among a plurality of extraction images means that more effective specific image can be used.
In another preferred configuration, the projection display apparatus includes an operating condition judging section that judges if the projection display apparatus is in a specific operating condition, wherein the specific image display control section displays the specific image when the specific operating condition is detected by the operating condition judging section.
This configuration can automatically determine when the projection display apparatus is in a specific operating condition, and display specific image that includes extraction image extracted by the image extraction section.
Specifically, the operating condition judging section is configured to detect as the specific operating condition at least one state selected from a state in which no image signal is being given to the projection display apparatus, and another state in which the projection display apparatus is within a prescribed period after startup.
In each of these states, in which the projection display apparatus cannot perform its normal display function, specific image that include extraction image extracted by the image extraction section can be automatically displayed.
A projection display apparatus according to a third aspect of the invention comprises: a frame memory for storing image data representing an image to be displayed; a image display signal generator for generating image display signals based on the image data stored in the frame memory; a electro-optical device for emitting light to form images responsive to the image display signals; a projection optical system for projecting light emitted by the electro-optical device; an operating condition judging section that judges if the projection display apparatus is in a specific operating condition; and a specific image display control section that displays the specific image represented by the specific image data when the operating condition judging section detects the specific display condition.
This configuration can automatically determine when the projection display apparatus is in a specific operating condition, and display specific images at such times.
For this, preferably the operating condition judging section detects as the specific operating condition at least one state selected from a state in which no image signal is being given, and a state in which the projection display apparatus is within a prescribed period after startup.
As described above, in each of these states in which the projection display apparatus cannot perform its normal display functions, specific image that include extraction image extracted by the image extraction section can be automatically displayed.
An image display apparatus according to a fourth aspect of the invention comprises: a frame memory for storing image data representing an image to be displayed; a image display signal generator for generating image display signals based on the image data stored in the frame memory; a electro-optical device for emitting light to form images responsive to the image display signals; an image extraction section that extracts at least a portion of an extraction target image selected arbitrarily from among images given externally as an extraction image; an extraction image memory for storing extraction image data representing the extraction image; and a specific image display control section that in a specific display condition displays the specific images represented by a specific image data including the extraction image data stored in the extraction image memory.
This image display apparatus has the same function and advantage as the projection display apparatus according to the fourth aspect. In a specific display condition selected by a user, the image display apparatus can display specific image that include arbitrarily extracted image in place of image given to the image display apparatus.
An image display apparatus according to a fifth aspect of the invention comprises: a frame memory for storing image data representing an image to be displayed; a image display signal generator for generating image display signals based on the image data stored in the frame memory; a electro-optical device for emitting light to form images responsive to the image display signals; an operating condition judging section that judges if the projection display apparatus is in a specific operating condition; and a specific image display control section that displays the specific image represented by the specific image data when the operating condition judging section detects the specific display condition.
This image display apparatus has the same function and advantage as the projection display apparatus according to the third aspect. It can automatically detect when the image display apparatus is in a specific display condition, and display specific images.
In accordance with a sixth aspect of the invention, a method of displaying images using a projection display apparatus having a light modulation unit to display an image based on image data given to the projection display apparatus by projecting the image on a screen, which comprises the steps of: extracting at least a portion of given first image data as an extraction image; preparing extraction image data representing the extraction image; generating overlaid image data by superimposing the extraction image on an original image represented by given second image data; driving light modulation unit responsive to the overlaid image data pixel by pixel basis; and projecting onto a screen overlaid images obtained by the light modulation unit.
This display method has the same function and advantage as the projection display apparatus according to the first aspect, enabling simultaneous display of related portions of multiple pages of images.
A display method according to a seventh aspect of the invention comprises the steps of: extracting at least a portion of a given extraction target image as an extraction image; preparing extraction image data representing the extraction image; and in a specific display condition, displaying a specific image represented by specific image data including the extraction image data.
This display method has the same function and advantage as the projection display apparatus according to the second aspect, enabling a specific image to be displayed even when the specific image is not being supplied from an external source.
A display method according to an eighth aspect of the invention comprises the steps of: judging if the projection display apparatus is in a specific operating condition; when it is judged that there is a specific operating condition, storing specific image data to a frame memory to display a specific image represented by specific image data.
This display method provides the same function and advantage as the projection display apparatus according to the third aspect, and is able to automatically determine when the projection display apparatus is in a specific operating condition, and display specific images at such times.
At least part of the functions of the above-described method steps and components of the invention can be implemented by a computer program recorded on computer-readable recording media such as floppy disks, CD-ROMs, opto-magnetic disks, punched cards, bar codes and other such printed symbols, internal storage device (including RAM and ROM) and external storage device.